Link retainer for well casing elevators



Dec. 22, 1936. Q D N 2,064,930

LINK RETAINER FOR WELL CASING ELEVATORS Filed Aug. '24, 1934 2 Sheets-Sheet l Dec. 22, 1936. c. A. LUNDEEN LINK' RETAINER FOR WELL CASING ELEVATORS Filed Aug. 24, 1954 2 Shee tS-SheGt Z Patented Dec. 22, 1936 UNITED STATES PATENT OFFICE LINK RETAINER FOR WELL CASING ELEVATORS Application August 24, 1934, Serial No. 741,249

8 Claims.

This invention relates to well casing elevators, such as are used for making a connection to well casing, drill pipe, tubing, and the like, in oil wells, for raising or lowering the same. More 5 particularly, the invention relates to that type of elevator which is in the form of a collar to engage the well casing or tubing, and provided with what is commonly known as a horizontally bifurcated ear to receive an elevator supporting link, as set forth in U. S. Patent No. 1,341,957, granted June 1, 1920, to E. C. Wilson. The present invention relates specifically to an improved means for retaining the elevator links in place in the elevator ears.

Nearly all of the well casing elevators in use today are. provided with horizontally bifurcated ears and with link retaining devices'similar to that shown in the Wilson patent. Usually the link retainer consists of only a bolt passed through the ends of the ears and may or may not be provided with a nut. The advantage of the construction shown in the Wilson patent is that when the bolt is in place and the nut is tight, the elevator link is positively locked in 25- place and the bolt serves to tie the open ends of the forks of the ear together and thus strengthens it. The disadvantage of using merely a bolt for connecting the forks of the ear, as in the Wilson link retainer, is that if the nut becomes loose the strengthening tie feature is lost, and if the nut comes off, both nut and bolt may drop and hit someone on the derrick floor. Many attempts have been made to overcome the disadvantage set forth above, but none of the proposed substitutes has proved successful for various reasons.

One of the objects of this invention is to produce an elevator having link-retaining means' of simple construction and operating in a simple manner to secure the supporting links against accidental dislodgement from the ears.

A further object is to provide a retaining arm, which is attached to one of the forks of the ear, and to provide means for ensuring that when the arm is connecting the forks of the ear the stresses in the upper fork will beimparted to the lower fork; also to ensure this regardless of whether the securing bolt used in the combination is tight or not.

A further object of this invention is to provide a construction of this type in which the parts of the combination are so related that the tying of the lower fork to the upper fork. for transmitting stresses is insured, and to provide a construction which can be relied upon not to come loose in use.

Further objects of the invention will appear hereinafter.

' The invention consists in the novel parts and combinations of parts to be described hereinafter, all of which contribute to produce an emcient link retainer for well casing elevators.

A preferred embodiment of the invention is described in the following specification, while the broad scope of the invention is pointed out in the appended claims.

In the drawings:

Figure 1 is a plan of an elevator embodying my invention, the supporting links being shown in cross-section;

Figure 2 is a front elevation of the elevator shown in Figure 1, withthe lower ends of the supporting links broken away;

Figure 3 is a vertical section on the line 3-3 of Figure 1, illustrating. details of the connecting arm between the forks and showing contiguous parts of the forks.

Figure 4 is an end elevation of one of the elevator ears with the connecting arm in position.

While this improvement can be applied to any type of casing elevator, in the present instance I have described it as applied to a type known as a center latch elevator.

Referring to the drawings, the elevator I comprises two gates or doors 2 and 3 connected together at the back by a hinge-pin 4, and the meeting faces of these doors are formed with arcua-te faces 5 to engage the side of the tubing or casing to be handled by the elevator. The forward ends of these doors are provided with handles 6 for opening and closing the elevator. These handles are disclosed and covered in a patent granted to Herbert E. Gran No. 2,025,047.

In this type of elevator, the elevator is provided with laterally and forwardly projecting ears 1, and each ear is bifurcated in a general horizontal direction, thereby forming an upper fork la and a lower fork lb with a throat 8 between the same. When the ear is open the lower end of the adjacent supporting link 9 may be passed into this throat so that the bight of the link can seat in a recess l0 formed in the underside of the upper fork.

In applying my invention to such an elevator, I provide a link-retaining arm ll corresponding to each ear. This arm is preferably permanently attached to one of the ears, and the flee end of the arm and the other fork are provided with correlated interlocking means so that the arm in its closed position will effectively tie the forks together for transmission of stresses from the upper fork to the lower fork. In the present instance, this arm II is attached by a transverse pivot pin I2 to the lower fork and provided with a stop lug I3 for supporting the arm in an open" position (as indicated in dotted lines in Fig. 3) for guiding the lower end of the adjacent link into the throat 8.

The free end of the arm II is provided with a tongue I4 that is received in a corresponding socket I5 in the upper fork 1a; and the end of thisfork has a similar tongue I6 that is received in a corresponding socket in the inner face of the arm II, and these two tongues I4 and I6 have faces II, the elements of which are struck on a radius having its center substantially at the axis of the pivot bolt II. These faces constitute engaging shoulders to tie the lower fork 1b to the upper fork Ia to impart stresses from the upper fork to the lower fork. This materially strengthens the construction at the ears I.

In order to secure the arm II in its closed, position, I prefer to provide its free end with a threaded stud or bolt I8 having a. nut or head I9 that seats on the upper end of the upper fork Ia, which is'formed with a slot 20 that permits the shank of the bolt to swing up through the slot when the head or nut I9 is screwed out sufficiently. When the bolt is tightened up, the head or nut I9 lies back of a guard lip or rib 2I that projects upwardly at the outer side of the nut;- and the head I9 is preferably provided with a cotter pin 22 (see Fig. 3) that extends through a diametrical opening in the nut with its ends projecting into opposite notches 23 in the guard 2I. The bolt need not be screwed up very tight, but if it is it will take some of the tension in the arm I I and distribute the strain upon it. The pin 22 should be a tapered pin and driven up tight or else a split pin, with its ends bent to hold it in place.

After each bolt I8 has been tightened up, I prefer to treat its lower end in the same way to prevent the bolt from being completely unscrewed. This may be accomplished by putting a cotter pin in the lower end of the bolt, but is preferably accomplished by peening over the lower end of the bolt to form a projection or slightly enlarged collar I8a. (See Fig. 3.)

It will be evident that the construction described at the upper end of the arm can be relied upon to keep the arm in its closed position, so that there is never any danger of the links getting out of the ears accidentally.

The elevator may be provided with a center latch 24 secured to a vertical rock-shaft 25 and urgedby a coiled spring 26 toward its latching position, at which time the head 21 of the latch is received in a corresponding socket 28 on the opposite door 3. This latch is disclosed and covered by a separate application filed in my name on the 25th day of August, 1934, Ser. No.

It is understood that the embodiment of the invention described herein is only one of the many embodiments this invention may take, and I do not wish to be limited in the practice of the invention, nor in the claims, to the particular embodiment set forth.

What I claim is:

l. A well-casing elevator with a laterally extending bifurcated supporting ear, comprising an upper fork and a lower fork, a link-retaining arm pivotally attached to one of said forks, the other fork and the free end of said arm having correlated interlocking means, and a bolt passing completely through the fork adjacent the said free end, and threaded into the free end of the arm for securing said arm in'a position in which it connects said forks, said bolt carrying tensile stresses and imparting the same from the upper fork to the lower fork.

2. A well casing elevator with a laterally extending bifurcated supporting ear, comprising an upper fork and a lower fork, a link retaining arm pivotally attached to one of said forks, the other fork and the free end of said arm having faces struck on a radius having its center substantially on the pivotal axis of the arm, said faces constituting shoulders, to engage each other so as to tie the forks together and impart stresses from the upper fork to the lower fork when under load, and means for detachably securing the free end of the arm to the end of the fork to retain the link between the forks.

3. A well-casing elevator with a laterally ex tending bifurcated supporting ear, comprising an upper fork and a lower fork, said upper fork having a recess in its underside adapted to receive a supporting link, a link-retaining arm pivotally attached to one of said forks, the other fork and the free end of said arm having correlated interlocking means, and a bolt carried on the free end of said arm, the adjacent fork having a slot extending completely through the same, and

through which the shank of said bolt may pass in connecting the arm to that fork. 4. A well-casing elevator with a laterally extending bifurcated supporting ear, comprising an upper fork and a lower fork, said upper fork having a recess in its underside adapted to receive a supporting link, a link-retaining arm, a pivot bolt positively pivoting said arm to one of said forks, the other fork and the free end of said arm hav ing correlated interlocking means, a bolt carried on the free end of said arm, the adjacent fork having a slot extending completely through the same, and through which the shank of said bolt may pass in connecting the arm to that fork, said bolt having a head, the slotted fork having a recess to receive the bolt head, and a guard on the fork to cooperate with the bolt head after the bolt has been tightened up to prevent the bolt from being swung out of the slot, said bolt and said arm constructed to transmit strain from the upper fork to the lower fork.

5. A well-casing elevator with a laterally extending bifurcated supporting ear, comprising an upper fork and a lower fork, said upper fork having a recess in its underside adapted to receive a supporting link, a link-retaining arm, a pivot bolt positively pivotally attaching said arm to one of said forks, the other fork and the free end of said arm having faces struck on a radius having its center substantially on the pivotal axis of the arm, said faces constituting shoulders to engage each other so as to tie the forks together and impart stresses from the upper fork to the lower fork, and a bolt passing through the fork opposite to the pivot of the bolt, with threads on its outer face, said arm having a threaded opening receiving the bolt threads for positively holding the arm in its closed position.

6. A well-casing elevator with a laterally extending bifurcated supporting ear, comprising an upper fork and a lower fork, said upper fork having a recess in its underside adapted'to receive a supporting link, a link-retaining arm, a pivot bolt positively pivotally attaching said arm to one of said forks, the other fork and the free end of said arm having faces struck on a radius having its center substantially on the pivotal axis of the arm, said faces constituting shoulders to come together when the arm is swung inwardly at its free end, so as to tie the forks together and impart stresses from the upper fork to the lower fork, and means for securing the free end of the arm to its adjacent fork to retain the link between the forks.

7. A well-casing elevator with a laterally extending bifurcated supporting ear, comprising an upper fork and a lower fork, said upper fork having a recess in its underside adapted to receive a supporting link, a link-retaining arm, a pivot bolt positively pivotally attaching said arm to one of said forks, the other fork and the free end of said am having correlated interlocking means, a bolt carried on the free end of said arm, the adjacent fork having a slot extending completely through the same from its end face inwardly, and through which the shank of said bolt may pass in connecting the arm to that fork, said bolt having a head, the slotted fork having a recess to receive the bolt head, and a guard on the fork to cooperate with the bolt head after the bolt has been tightened up to prevent the bolt from being swung out of the slot, and means for locking said bolt head to its adjacent fork with the bolt in a tightened up condition.

8. A well casing elevator with a laterally extending bifurcated supporting ear, comprising an upper fork and a lower fork, a link retaining arm pivotally attached to one of said forks, the other fork and the free end of said arm having faces struck on a radius having its center substantially on the pivotal axis of the arm, said faces constituting shoulders to engage each other so as to tie the forks together and impart stresses from the upper fork to the lower fork when under load, and a bolt mounted in the free end of the arm for securing the arm to the opposite fork, the opposite fork having a slot to receive the bolt, and the bolt having a head seating on the fork adjacent the slot.

CHESTER A. LUNDEEN. 

